diff --git a/Ciphers/RSAAlgorithm.js b/Ciphers/RSAAlgorithm.js
new file mode 100644
index 0000000000..347e2531a1
--- /dev/null
+++ b/Ciphers/RSAAlgorithm.js
@@ -0,0 +1,106 @@
+// RSAAlgorithm.js
+
+/**
+ * Generates the greatest common divisor of two numbers.
+ * @param {number} a - First number.
+ * @param {number} b - Second number.
+ * @returns {number} - The GCD of a and b.
+ */
+export function gcd(a, b) {
+ if (b === 0) {
+ return a
+ }
+ return gcd(b, a % b)
+}
+
+/**
+ * Calculates modular inverse using Extended Euclidean Algorithm.
+ * @param {number} e - The number to find inverse for.
+ * @param {number} phi - The modulus.
+ * @returns {number} - The modular inverse of e mod phi.
+ */
+export function modInverse(e, phi) {
+ let [m0, x0, x1] = [phi, 0, 1]
+
+ if (phi === 1) {
+ return 0
+ }
+
+ while (e > 1) {
+ let q = Math.floor(e / phi)
+ ;[e, phi] = [phi, e % phi]
+ ;[x0, x1] = [x1 - q * x0, x0]
+ }
+
+ if (x1 < 0) {
+ x1 += m0
+ }
+
+ return x1
+}
+
+/**
+ * Performs modular exponentiation.
+ * @param {number} base - Base number.
+ * @param {number} exponent - Exponent.
+ * @param {number} modulus - Modulus.
+ * @returns {number} - (base^exponent) % modulus.
+ */
+export function modPow(base, exponent, modulus) {
+ if (modulus === 1) return 0
+ let result = 1
+ base = base % modulus
+
+ while (exponent > 0) {
+ if (exponent % 2 === 1) {
+ result = (result * base) % modulus
+ }
+ exponent = Math.floor(exponent / 2)
+ base = (base * base) % modulus
+ }
+
+ return result
+}
+
+/**
+ * Generates RSA keys.
+ * @param {number} p - A prime number.
+ * @param {number} q - A prime number.
+ * @returns {{publicKey: {e: number, n: number}, privateKey: {d: number, n: number}}}
+ */
+export function generateKeys(p, q) {
+ const n = p * q
+ const phi = (p - 1) * (q - 1)
+
+ let e = 2
+ while (e < phi && gcd(e, phi) !== 1) {
+ e++
+ }
+
+ const d = modInverse(e, phi)
+
+ return {
+ publicKey: { e, n },
+ privateKey: { d, n }
+ }
+}
+
+/**
+ * Encrypts a message with a public key.
+ * @param {number} message - The message to encrypt (as a number).
+ * @param {{e: number, n: number}} publicKey - The public key.
+ * @returns {number} - The encrypted message.
+ */
+export function encrypt(message, publicKey) {
+ return modPow(message, publicKey.e, publicKey.n)
+}
+
+/**
+ * Decrypts a cipher with a private key.
+ * @param {number} cipher - The encrypted message (cipher).
+ * @param {{d: number, n: number}} privateKey - The private key.
+ * @returns {number} - The decrypted message.
+ */
+export function decrypt(cipher, privateKey) {
+ return modPow(cipher, privateKey.d, privateKey.n)
+}
diff --git a/Ciphers/test/RSAAlgorithm.test.js b/Ciphers/test/RSAAlgorithm.test.js
new file mode 100644
index 0000000000..ac1d0e540f
--- /dev/null
+++ b/Ciphers/test/RSAAlgorithm.test.js
@@ -0,0 +1,14 @@
+// RSAAlgorithm.test.js
+import { describe, it, expect } from 'vitest'
+import { generateKeys, encrypt, decrypt } from '../RSAAlgorithm.js'
+
+describe('RSA Algorithm', () => {
+ it('should encrypt and decrypt correctly', () => {
+ const { publicKey, privateKey } = generateKeys(61, 53) // two primes
+ const message = 65
+ const cipher = encrypt(message, publicKey)
+ const decrypted = decrypt(cipher, privateKey)
+
+ expect(decrypted).toBe(message)
+ })
+})
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